Changeset 35661 for main/trunk/greenstone3/gs3-setup.sh

Timestamp:

2021-10-21T18:58:59+13:00 (3 years ago)

Author:

davidb

Message:

Adjusted solution to how -noclasspath is explicitly set by Greenstone3 so we don't get the ant vs ant.jar cross-contamination problem. Previously it had been dealt with inside the GLI GS3ServerThread.java code (explicitly adding it in). In this update, the ANT_ARGS environment variable is set in gs3-setup.bash, thereby triggering the same outcome, but only needs to be done in one place.

File:

• main/trunk/greenstone3/gs3-setup.sh (modified) (2 diffs)

main/trunk/greenstone3/gs3-setup.sh

@@ -573 +573 @@
 # Ant
 echo "Checking for Ant"
-#Note: No longer need to print out info about minimum version of Ant needed
-#  for Greenstone3 (v1.7.1 at the time of writing this comment!), as this is
-#  now explicitly tested for in the build.xml file, and an error message generated
-#  if not new enough
+
+# Note 1: No longer need to print out info about minimum version of
+#  Ant needed for Greenstone3 (v1.8.2 at the time of updating this
+#  comment!), as this is now explicitly tested for in the build.xml
+#  file, and an error message generated if not new enough
+
+# Note 2: The setting of ANT_ARGS to '-noclasspath' flag below is to
+#   void "cross-contamination' between this setup file -- which sets
+#   CLASSPATH to include all the jars in <gsdl3srchome>web/WEB-INF,
+#   including an ant.jar -- and what is needed to cleanly run the
+#   'ant' script and have it find the matching 'ant.jar' that goes
+#   with it (i.e. is the same version).  For example we want the
+#   system installed /usr/bin/ant to find /usr/share/ant/lib/ant.jar
+#
+#   Undesirable behaviour can occur, however, when the 'ant' that is
+#   run is the one found on PATH, and a different ant.jar is found (as
+#   can occur when CLASSPATH is set).  For this pattern of running the
+#   'ant' script the 'ant.jar' that is in Greenstone's web/WEB-INF
+#   area is found.  This Greenstone ant.jar file (at the time of
+#   writing) is for ant v.1.8.2, and causes some of the Java
+#   properities ant uses to changed.  Even if your installed 'ant' is
+#   (say v1.10.9) and the JDK you are running is JDK11, as a
+#   consequence of finding the older ant.jar file, ant.version is set
+#   to 1.8.2 and ant.java.version to 1.7.  As a consequence of this,
+#   the Greenstone3 build.xml fails to run as its minimum Java version
+#   needs to be >=1.8
+#
+#   In looking at how to address this issue, updating the version of ant.jar
+#   was considered.  However, taking this approach means there will aways be
+#   a risk of a version mismatch between a system installed 'ant' and
+#   the version of ant.jar Greenstone includes.
+#
+#   The approach taken here, then, is to more carefully control the
+#   launching of ant.  By setting ANT_ARGS to -noclasspath, the 'ant'
+#   script is directed not to use CLASSPATH, thereby avoidig the
+#   cross-contamination problem.
+#
+#   Of further note, in the event ANT_HONE is set, then the situation
+#   we are in is much simpler, as the cross-contamination problem
+#   doesn't arise.  This is because the 'ant' script explicitly sets
+#   ANT_LIB, based on ANT_HOME, to explicitly pick out ant.jar file
+#   that goes along with the script.
+#
 
 if [ -x "$GSDL3SRCHOME/packages/ant/bin/ant" ] ; then
@@ -587 +626 @@
     addtopath PATH "$ANT_HOME/bin"
     echo "  - `ant -version`"
-  else 
-    which ant &> /dev/null
+  else
+    # which ant &> /dev/null
+    # Posix friendly way to determine if a program exists:
+    #   https://stackoverflow.com/questions/592620/how-can-i-check-if-a-program-exists-from-a-bash-script
+    command -v ant &> /dev/null
+      
     if [ "$?" = "0" ] ; then
       echo "  - System install ant detected"
+
+      if [ "x$ANT_ARGS" = "x" ] ; then
+      ANT_ARGS="-noclasspath"
+      else
+      ANT_ARGS="-noclasspath $ANT_ARGS"
+      fi
+      export ANT_ARGS
+
       echo "  - `ant -version`"
+
     else
       echo "  - WARNING: Failed to find 'ant'"